Tisis is a very beautiful young Ruthgari woman with pale skin, hazel-colored eyes and blond hair. Her face is heart-shaped and her body is quite curvaceous. Her movements are described graceful and resembling a dance.
Tisis comes from a noble family, but since they were on the losing side of the war of the Prisms she was sent as a hostage on the Jaspers at a young age. The current head of the family- Eirene Malargos is her elder sister. Since some people believe her sister has an aversion for men and will not have any children, Tisis is expected to inherit the family fortune.
While Tisis is a talented green drafter, she lacks any combat training. Moreover, her pale skin is considered a great disadvantage in combat, as the drafted colors are easily seen by the enemy. She posses some medical skills though, which is a part of the education of all drafters of noble descent.
The Black Prism
As her pale skin and beauty are favored in religious ceremonies, she is chosen to represent the green color during Kip's initiation. However, as the Malargos family supported Dazen during the war, they consider Gavin responsible for the loss of their family members and every Guile their enemy. The ceremony gives her a chance to hurt Gavin by sabotaging Kip's initiation. Kip passes nonetheless but after the trial her actions are questioned by Gavin.
The Blinding Knife
She re-appears in the second book as a new member of the Spectrum. Gavin suspects that Andross has arranged her position and is controlling her vote. At the meeting she constantly opposes Gavin and is finally removed from the council, as the satrapy represented by her - Tyrea had fallen to enemies and was disbanded. Later Gavin and Andross have several meetings at which Tisis is also discussed. Andross insists that his son should marry her, as her family is rich and powerful. Gavin oposes his father's decision, as he is in love with another woman. Andross replies that if Gavin doesn't want her, he will marry her himself.
The Broken Eye
Some time later Kip's room is trashed and his money are stolen. He suspects this to be another provocation from Andross and bursts in his chambers in order to confront him about it. There he sees the half-naked Tisis in his grandfather's bed and starts insulting and provoking her. Tisis throws a vase at him, but is slapped by Andross and falls unconscius. Andross offers Kip the same thing he offered Gavin- to marry Tisis. He suspects she has overheard their argument and will try exploit the family schism by seducing Kip. Kip still has some doubts, even though Andross assures him he has not yet slept with the girl.
Andross is soon proved more or less right. During a visit to the public baths, Kip is surprised by the naked Tisis. But instead of seducing him, Tisis opens up to Kip. She confesses that she never meant to fail his trial and that her family suspects that Andross is planning to get them killed, probably by allowing the war to consume their lands. She was asked by her sister to marry Gavin and after his rejection she was supposed to marry Andross Guile. Tisis states, that all she wants is to protect her people and is ready to do whatever it takes. Kip is moved by her bravery and apologizes for insulting and misjudging her. Tisis then asks him to marry her and quickly runs away, stealing the only bath robe.
Andross discusses the proposal and asks Kip to run away with Tisis. Kip is supposed to be running from his grandfather, but in reality should act as his spy in the Malargos family. Kip marries Tisis on the docks and they board the ship to Ruthgar in secret, as officially she is a hostage and is not allowed to leave. However, Kip states that he will be traveling to the Blood Forest, to fight the Color Prince. Tisis is offered a chance to go home with her sister, but chooses to stay with Kip instead.
The Blood Mirror
On the ship Tisis and Kip are expected to consummate their marriage within seven days, otherwise their marriage is considered void. They are unable to do it, and choose to simulate it by jumping on the bed and moaning loudly. On the next morning their companions reveal there were some bets whether they would actually succeed.
On the ship Tisis also insists on becoming a full member of the Mighty and participate in their actions against the Color Prince. They are not pleased with that decision, especially Winsen. He tries to attack her verbally and make her look incompetent on several occasions.